Dtv Transmitter and Method of Coding Data in Dtv Transmitter

1. A broadcast transmitter comprising: a generator for generating a broadcast signal having mobile data and known data; and a transmitting unit for transmitting the broadcast signal to one or more broadcast receivers, wherein the generator is for generating the broadcast signal by: encoding the mobile data for first error correction; convolutional encoding the encoded mobile data to output at least 2 bits from a first bit of the encoded mobile data; Reed-Solomon (RS) encoding the convolutional encoded mobile data by adding first parity data to the convolutional encoded mobile data; trellis encoding the RS-encoded mobile data in a trellis encoding unit, wherein at least one memory included in the trellis encoding unit is initialized by initialization data just prior to the known data; calculating second parity data based on the initialization data; replacing the first parity data with the second parity data; and outputting the replaced second parity data to the trellis encoding unit.

2. The broadcast transmitter of claim 1 , wherein the generator is for convolutional encoding the encoded mobile data by: inputting the first bit of the encoded mobile data to a modulo adder; inputting an output bit of the modulo adder to a first memory; inputting an output bit of the first memory to a second memory; and inputting an output bit of the second memory to the modulo adder.

3. The broadcast transmitter of claim 2 , wherein the at least 2 bits include the first bit of the encoded mobile data and the output bit of the first memory.

4. A method of processing digital broadcast data in a broadcast transmitter, the method comprising: generating, by a generator, a broadcast signal having mobile data and known data; and transmitting, by a transmitting unit, the broadcast signal to one or more broadcast receivers, wherein generating the broadcast signal comprises: encoding the mobile data for first error correction; convolutional encoding the encoded mobile data to output at least 2 bits from a first bit of the encoded mobile data; Reed-Solomon (RS) encoding the convolutional encoded mobile data by adding first parity data to the convolutional encoded mobile data; trellis encoding the RS-encoded mobile data in a trellis encoding unit, wherein at least one memory included in the trellis encoding unit is initialized by initialization data just prior to the known data; calculating second parity data based on the initialization data; replacing the first parity data with the second parity data; and outputting the replaced second parity data to the trellis encoding unit.

5. The method of claim 4 , wherein convolutional encoding the encoded mobile data comprises: inputting the first bit of the encoded mobile data to a modulo adder; inputting an output bit of the modulo adder to a first memory; inputting an output bit of the first memory to a second memory; and inputting an output bit of the second memory to the modulo adder.

6. The method of claim 5 , wherein the at least 2 bits include the first bit of the encoded mobile data and the output bit of the first memory.